<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>15-属性描述符2</title>
</head>

<body>
    <script>
        /* 
           configurable: false (允许删除/编辑)
           enumerable: true    (可枚举)(for-in)
           value: 1            (值)
           writable: true      (可写)
       */
        var obj = {
            a: 1,
            b: 2,
            c: 3,
        };
        Object.defineProperty(obj, "b", {
            configurable: false,
            // configurable:true,
            // enumerable:true,
            enumerable: false,
            value: 22,
            writable: true,
            // writable:false,
        });
        // delete obj.b
        obj.b = 99;

        for (let key in obj) {
            console.log(key);
        }
        console.log(obj);
       // 注意：默认值
    </script>
</body>

</html>